My breast usually feel sore before i start my period but never have felt firm, both of my entire breast are sore and firm and i noticed this started 10days before period is due and it’s been sore and firm for 3 days now and today I’ve started to experience nausea and eating didn’t even help with the nausea. I had unprotected sex right after my period ended on cd 6 my periods are irregular last month i was late and had a cycle of 35 days I’m wondering if i could have a short cycle this month because of that long cycle last month? It’s been almost 3 weeks since we’ve had sex but I’m not due for my period for another week. Could it be pregnancy related or no?